Nikita, I take it you're speaking of the ladder search pattern FATs. Seeing they are electric it strikes my funny as to why an escort would know where it came from if it is coming back from it's original course when it strikes any ship. But for some reason they do, unless they were tracking it to begin with.
Now my question... which side of the convoy did the escorts come from looking for you? If the starboard side, then I wouldn't think so as they convoy should mask you. But if from the port side where you are, it's a good possibility. Especially if they are closer than 2000 meters. If over that they shouldn't know as the engine noises from the convoy should mask you. But then again, SHIII's sonar detection works in mysterious ways and is hard to figure out at times...... actually all the time IMHO.
LOL